December marks the full onset of winter in Chiang Mai. City temperatures are cool to rather cold, especially in the early mornings and at night. In the mountains, the weather is very cold to extremely cold, with temperatures easily dropping to single digits. Therefore, clothing preparation differs significantly between the city and the mountains.

Chiang Mai City Weather in December

In Chiang Mai city areas, such as Tha Phae Gate or Nimman, the weather is comfortably cool throughout the day. Some days may have mild sunshine during the day, making it feel warm. However, in the early mornings before sunrise and at night after sunset, temperatures drop rapidly, and cool winds blow through. The air is drier than in other regions, making it feel colder than expected.

Recommended Clothing for the City:

  • Long-sleeved shirts: Not too thick, such as cotton or linen, for daytime wear.
  • Light jacket or sweater: For layering in the mornings and evenings.
  • Long pants: Jeans or comfortable fabric trousers.

Mountain Weather in December: How Cold Does It Get?

In various mountains around Chiang Mai, such as Doi Inthanon, Doi Suthep, or Mae Kampong, the weather is significantly colder than in the city. Temperatures on high mountain peaks like Doi Inthanon can easily drop below 10 degrees Celsius, and sometimes even reach freezing point. Strong winds on the mountaintops will make it feel even colder than the thermometer reading. It is advisable to check the weather forecast for each specific area, especially the mountain peaks, as city and mountain temperatures differ greatly.

Recommended Clothing for Mountain Trips:

Layering is the best approach, as it allows you to adjust to changing temperatures throughout the day:

  • Base Layer: Long-sleeved shirt that wicks moisture well, such as merino wool or synthetic fabric, to maintain body temperature.
  • Mid Layer: Fleece jacket or thick sweater for warmth.
  • Outer Layer: Thick winter jacket or a windbreaker that is slightly water-resistant, as mountaintops have strong winds and may have fog or mist.
  • Additional Winter Accessories: A wool hat, gloves, and a scarf are essential, especially if you plan to visit very high peaks.
  • Footwear: Comfortable, ankle-covering, and slightly non-slip shoes will help you walk more easily on uneven or wet terrain.

Important Considerations and Additional Information

  • Motion Sickness: Some mountain roads have many curves, such as the route up Doi Inthanon or the road to Mae Kampong, which can easily cause motion sickness. It’s advisable to prepare motion sickness medication and choose a seat with a wide view. For more information on this, you can read about Electric vs. Gasoline Cars: How Different for Those Prone to Motion Sickness on Mountain Drives?
  • Restrooms: Restrooms are available at major stop points on the mountains, such as national park offices or restaurants. However, some parts of the route may not have frequent restroom facilities. It’s advisable to use restrooms before departing or whenever you encounter a stop with facilities.
  • PM 2.5 Dust: Generally, December is still a period with relatively good air quality and low dust levels. Nevertheless, it’s always recommended to check the weather and dust levels before each trip.

What to Know If You Book a Private Driver for Mountain Trips

If you choose to use a private car service with a driver for your mountain trips, it will allow you to travel comfortably without worrying about winding roads or finding parking, and you can adjust your stops as appropriate.

  • Full-Day Doi Inthanon Package: An ideal option for those who specifically want to visit Doi Inthanon. The total travel time is approximately 8–10 hours, with a round trip distance of about 200 km from Chiang Mai city.
  • Custom Full-Day Package: For those who wish to visit other mountains, such as Doi Suthep + Bhubing Palace (approx. 35 km round trip) or Mae Kampong + Hot Springs (approx. 92 km round trip). This package takes approximately 8 hours, with a total distance not exceeding 150 km.

What’s Included in the Package Price:

  • Driver service
  • Energy costs throughout the trip (Our cars are electric, so you don’t have to worry about refueling)
  • Toll fees along the agreed route
  • Insurance as per conditions stated before booking
  • Cold drinking water and child seats upon advance request
  • USB-C cable for phone charging
  • Ability to adjust the order of stops within the agreed scope

What’s Not Included in the Package Price:

  • Entrance fees to various attractions and national parks
  • Food and beverages
  • Driver’s tip
  • Additional cost if a licensed tour guide is requested
  • Overtime beyond the package duration will be charged at 300 THB per hour.
  • If the distance exceeds the agreed limit, the price will be informed before confirmation.

Booking and Service Hours:

  • A 50% deposit is due 7 days prior to the travel date to confirm the booking. In case of subsequent cancellation, the deposit is non-refundable.
  • Vehicles operate from morning until evening. You can choose a departure time that suits your plan. It is recommended to depart when there is sufficient daylight for sightseeing and to return to your accommodation before dark for safety and convenience.

Summary

Chiang Mai in December offers comfortably cool weather in the city but is very cold on high mountains like Doi Inthanon. Preparing multiple layers of clothing, including long-sleeved shirts, sweaters, windbreakers, as well as winter accessories like hats, gloves, and scarves, is essential, especially if you plan to experience the cold on the mountaintops. Don’t forget to check the specific weather conditions before departing and prepare motion sickness medication if you are prone to it.